Mainstream Update

Mainstream Update

ATI's much delayed R600 core and architecture initially failed to convince critics and consumers when it was finally released last year but the company has moved quickly to shrinking the core to 55nm, which resulted in the Radeon HD 3000 series merely six months after the R600's debut. While ATI still had to concede the high-end to NVIDIA, it did slow the worrying erosion of ATI's market share. In fact, the graphics division was doing fairly well as opposed to the company's CPU business.

Early this year, this relatively successful die shrink was extended to the lower and mainstream segments. Christened the Radeon HD 3600 and 3400 series, these new graphics cards are basically 55nm refreshes of the Radeon HD 2600 and 2400 series respectively, with updated specifications that support the latest standards being pushed aggressively by ATI as a way to distinguish its products from its competitor, like Shader Model 4.1 and DirectX 10.1 support . They are also the first ATI products to natively support DisplayPort, the new audio/video display interface that will compete against HDMI. Here's how the newcomers stack up:-

Comparing the Radeon HD 3650

Model

ATI Radeon HD 3650 512MB

ATI Radeon HD 3850 256MB

NVIDIA GeForce 8600 GTS 256MB

NVIDIA GeForce 8600 GT 256MB

ATI Radeon HD 2600 XT 256MB GDDR4

Core Code

RV635

RV670

G84

G84

RV630

Transistor Count

378 million

666 million

289 million

289 million

390 million

Manufacturing Process (microns)

0.055

0.055

0.08

0.08

0.065

Core Clock

725MHz

670MHz

675MHz

540MHz

800MHz

Stream Processors

24 Shader units consisting of 120 Stream Processors

64 Shader units consisting of 320 Stream Processors

32 Stream Processors

32 Stream Processors

24 Shader units consisting of 120 Stream Processors

Stream Processor Clock

725MHz

670MHz

1450MHz

1190MHz

800MHz

Texture Mapping Units (TMU) or Texture Filtering (TF) units

8

16

16

16

8

Raster Operator units (ROP)

4

16

8

8

4

Memory Clock

1000 - 1600MHz DDR2/3

1660MHz DDR3

2000MHz DDR3

1400MHz GDDR3

2200MHz DDR4

DDR Memory Bus

128-bit

256-bit

128-bit

128-bit

128-bit

Memory Bandwidth

up to 25.6GB/s

53.1GB/s

32.0GB/s

22.4GB/s

35.2GB/s

Ring Bus Memory Controller

256-bit (for memory reads only)

512-bit

NIL

NIL

256-bit (for memory reads only)

PCI Express Interface

PCIe ver 2.0 x16

PCIe ver 2.0 x16

x16

x16

x16

Molex Power Connectors

No

Yes

Yes

No

Yes

Multi GPU Technology

Yes (CrossFire)

Yes (CrossFire)

Yes (SLI)

Yes (SLI)

Yes (CrossFire)

DVI Output Support

2 x Dual-Link

2 x Dual-Link

2 x Dual-Link

2 x Dual-Link

2 x Dual-Link

HDCP Output Cable?

Yes

Yes

Yes

Vendor dependent

Yes

Street Price

~US$90 - 109

~US$149 - 169

~US$109 - 149

~US$90 - 120

~US$90 - 109

As you can see from the specifications, the Radeon HD 3650 is exactly like the Radeon HD 2600 XT in terms of its hardware, with the same number of unified shaders and ROPs. The limitations of the older chipset are also evident, like the 128-bit memory bus. On the plus side, the die shrink means there's no longer a need for a power connector due to its lower power draw and in the same vein, ATI's power saving technology, PowerPlay is also present to reduce power consumption during idle. ATI has managed to optimize the core, leading to a slightly smaller transistor count of 378 million. Finally, there's PCIe 2.0 x16 support, making it suitable for newer motherboards, along with CrossFireX support, allowing it to be linked to multiple ATI GPUs of differing speeds.

However, given the similarities in hardware processing power between the Radeon HD 2600 and 3600 series, the lower clock speed of the Radeon HD 3650 does seem to hint that ATI is not that concerned with the performance. Instead, this new SKU appears to be about updating features and bringing the company's mainstream products in line with its existing Radeon HD 3800 series. Are the lower clocks going to severely hurt this SKU? To find out, we'll be looking at a Radeon HD 3650 graphics card from MSI.